By Craig Martin, USACEFebruary 23, 2018
As one of the predominant small harbors at the mouth of the Connecticut River in the early 1900's the North Cove Federal Navigation Project in Old Saybrook, Connecticut has seen its use slowly change over the years from a harbor of refuge for light commercial vessels at its inception to a fleet almost entirely comprised of small to medium sized recreational vessels used mainly from the spring through fall months. The project has been maintained a number of times since it was authorized, with the most recent past dredging event in 2008. At that time, 175,000 cubic yards of sediment were removed, but due to funding constraints the authorized dimensions of the project were not obtained. The current cycle of maintenance was initiated by the town of Old Saybrook when availability of the project began to be impacted during times of low tide.
Dredging areas include the 11-foot deep entrance channel, 11-foot deep anchorage and 6-foot deep anchorage. DonJon Marine Company, Inc., of Hillside, New Jersey, is performing the work under a $4,283,562.50 contract awarded Sept. 20, 2017. The company began dredging activities on Nov. 14, 2017, and has removed about 230,000 cubic yards of material from the project so far. Approximately 286,000 cubic yards of predominantly silty sediment will be removed by mechanical dredge.. Approximately 56,000 cubic yards of material still needs to be dredged from the 6-foot anchorage area by the coordinated dredging window ending on March 31.
The state of Connecticut is the sponsor for the project and bonded $7.5 million in 2015 for permitting, design and construction of the maintenance dredging project. The project sponsor was instrumental in getting the funding needed to move forward with the project. With the extensive number of shallow draft projects nationwide competing for limited federal funding, this maintenance event would not have been possible without the financial support of the state of Connecticut and commitment of its Port Authority to make it happen. This project is unique for the District employing a second trans-loading dredge to transfer shoal material from small hopper scows used to access shallow portions of the project to large capacity dump scows.
After the trans-loading process is complete the large dump scows are hauled to the Central Long Island Sound Disposal Site, about 35 miles away from the project, and placed at predesignated coordinates. Additionally, the project will deploy a turbidity curtain during the latter stages of the project to allow dredging to continue into time of year restrictions to protect sensitive species.
Despite equipment breakdowns and cold weather resulting in several inches of ice within the project, the contractor expects to complete the project this dredging season.